The proposed research is designed to obtain a basic understanding of the electrophysiology, pharmacology and morphology of mammalian parasympathetic ganglion transmission. Local neuronal interactions which occur during ganglionic transmission will be analyzed in cat vesical pelvic ganglia (VPG) using extracellular (sucrose-gap), intracellular and iontophoretic techniques coupled with differential interference microscopy. Four types of local neuronal interactions will be investigated in cat parasympathetic VPG: 1) slow modulatory potentials (Griffith, Gallagher and Shinnick-Gallagher, 1979b), 2) spontaneously active cells (Griffith et al., 1979a), 3) intrinsic cell-to-cell communications, and 4) an adrenergic inhibitory mechanism (deGroat and Saum, 1971). In addition, the morphology of the three distinct cell types identified within the VPG (Griffith et al., 1979a) will be compared using intracellularly injected fluorescent dye. The sites, mechanisms, and functional significance of the local neuronal interactions which occur in the bladder ganglia will be determined. Analysis of the underlying mechanisms of these local neuronal interactions may lead to a better understanding of autonomic function, particularly parasympathetic ganglionic transmission, as well as "higher" brain functions in the central nervous system which may be involved in memory, learning, and behavior.